Steering mechanism.



r v I 'Patente d my 29, I902. F. E. ALLEN & a. n. DANFO'RTH'.

STEERING MECHANISM.

(Application med Dec. 17, 1960.

(No Model.)

\w v QQ INVENTEIRSZ UNITED STATES.

PA-TENT OFFICE.

FREDERICK E. ALLEN, OF BOSTON, AND RAYMOND H. DANFORTII, OF SALEM,MASSACHUSETTS, ASSIGNORS TO- THE IMPROVEMENTS MANUFACTURING COMPANY, O

PORATION OF MAINE.

F BOSTON, MASSACHUSETTS, A COR- STEERING-MECHANISM.

SPECIFICATION forming part of Letters Patent No. 705,892, dated July 29,1902. Application filed December 17, 1900. Serial No. 40,068. (Nomodel.)

To aZZ whom it may concern:

' Be it known that we, FREDERICK E. ALLEN,

ing is a specification.

This invention relates to steering mechanism of the non-reversing orlocked type ad apted to be applied to automobiles and other ve-' hiclesor to the rudders of boats.

The invention involves the use of a grooved convoluted locking andactuating cam operating upon a member which has a circular stud engagedwith a single convolution only of the groove of said cam at a time, themechanism being thereby distinguished from devices in which a worm orother gear coacting with a multitoothed complemental gear member isemployed.

The present invention consists in certain novel features of constructionand. arrange-' ment, which we will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a plan view of a steering mechanism organized inaccordance with our invention. Fig. 2 represents a side elevation ofapart mounted on the vehicle body. Fig. 3 represents afront elevation ofsaid part. transverse vertical section thereof. Fig. 5 represents a planview showing another embodiment. Fig. 6 represents a front elevationthereof. Fig. 7 represents a side elevation.

The same reference characters indicate the a knuckles withone arm 5 of.a bell-crank lever same parts in all of the figures.

The principal objects of the invention are to enable the cam andassociated parts when it is desired to locate the same upon thevehicle-body to be mounted closeto the body,

while at the same time maintaining their proper relation with themechanism of the underframe of the vehicle, and also to prevent backlashand provide for different rates of movement of the member coacting withthe cam in different portions of the stroke of the Fig. at represents acam. It has been proposed'heretofore to employin a steering mechanism acam of very steep pitch, so as to obtain the full range of movement ofthe steering-Wheels in a partial rotation of the cam. It is difficult tomake this form of mechanism sufficiently compact to render-its usedesirable on .vehicles, and

.it is further necessary to make the pitch of the cam so steep that auniform locking action, with absence of binding or cramping atall pointsof the stroke of the cam,is not easily attainable. Steering mechanismsusing a worm or other form of locking-gear coacting with a multitoothedcom-plemental gear are open to this limitation, among others, that themovement of the complemental member in each cycle or revolution of thelocking-gear is a repetition of its movement in other cycles orrevolutions, whereas it may be desired to obtain a different rate ofmovement at the ends of the stroke of the complemental member than inthe intermediate portion of said stroke. 0 ur invention being distinctlya convolute-cam mechanism enables us to obtain this difierence ofmovement in different parts of the stroke, and the construction which weadopt further avoids backlash and overcomes .friction. I

Referring at first to Figs. 1 to 4, in which only as much of a vehicleis shown as to enable the relation of the steering mechanism to thevehicle to be understood, 1 represents the cross-frame, forming a partof the underframe of a vehicle andhaving the steering- Wheels 2 2mounted on the usual knuckles 3 3, which are pivoted or swiveled to theends of said cross-frame. Rods 4L 4 connect said whose stem 6 isvertically'journaled in bearings on the cross-frame 1, the other arm 7of the vehicle-body. On the under side of the floor 8 of thevehicle-body is bolted the frame 9 of the cam mechanism, and in arms 1011, projecting downwardly from the top plate 12 of said frame, ismounted a horizontal pintle 13, upon which is rotatively journaled a cam14, having a small bevel-pinion 15 on its hub.

16 is a steering-stem, to the upper end of which the steering-handle isattached, said stem being journaled in a bearing 17 on the frame 9 andhaving secured to its lower end a large bevel gear-segment 18, meshingwith the bevel-pinion 15, whereby when the stem or spindle 16 is rotatedin its bearing the cam 14 will be revolved, the relation of the gears 1518 being such that a partial rotation of the spindle 16 imparts one ormore complete rotations to the cam. I

In the upper portion of the arm 10 and in a second arm 19, projectingdownwardly from the top plate 12, is mounted a horizontal pintle 20,upon which is journaled a downwardly-projecting arm or lever21,whoselower end is connected by a rod or link 22 with the arm 7 of thesteering connections on the underframe. The length of thedownwardlyprojecting portion of lever 21 is such that the link 22 innormal position will be substantially horizontal, this being desirablein order to obtain'a straight push or pull from lever 21 to the arm 7and, furthermore, to

avoid disturbing the position of the steeringwheels 2 by the verticalmovement of the'underframe 1. Alike result could be obtained by mountingthe lever 21 and cam- 14 in a horizontal position and dropping the wholecam mechanism down to the level of the underframe 1; but this wouldexpose the cam mechanism more than in the arrangement illustrated andwould involve the use of additional supports, whereas by the arrangementillustrated the cam mechanism can be made very compact and mounteddirectly upon the floor of the vehicle-body.

The cam 14 is provided with a groove 23, which constitutes the actingportion or course of said cam, said groove being a continuing ornon-returning one of uniform width throughout, having a number ofcomplete turns or convolutions. The lever 21 is provided with a shortlaterally-projecting arm 24, having a single stud or tooth 25 occupyingthe camgroove 23 and provided with an antifrictionroller 26,constituting a circular stud, engaging the sides of the groove. Thissingle stud is made to fit the groove accurately in all portions of theoperating length of said groove, thereby doing away with backlash.

The single roller-stud also operates with less friction than would theordinary gear-teeth of a gear-segment in mesh with a worm or otherconvoluted gear or even than a multitoothed member having roller studsor teeth in mesh with more than one convolution of the locking-gear at atime.

In the middle position of the steering-wheels the stud 25 is in anintermediate portion of the cam-groove 23, and the vehicle is steered toone side or the other by rotating the steering-spindle 16 andthrowingthestud 25 into one or' the other of the end portions of thecam-groove, thereby oscillating the lever 21 on either side of a middleposition. The path of movement of the stud 25 is an are having thepintle 20 as a center and is at all portions of the stroke of the camsubstantially normal to the direction of the cam-groove 23, so that thereversing strain or tendency to oscillate the lever 21, due toirregularities in the roadway encountered by the steeringwheels 2, isunable to effect the rotation of the cam 14, and the lever 21'isaccordingly locked in all portions of the stroke of the cam. Thecam-groove being in the form of a coil or series of convolutions, itspitch is gradual and allows for an effective locking action at allpoints in the stroke of the cam, while at the same time keeping the sizeof the parts at a minimum and avoiding any bind= ing or cramping actionor any undue strains. The use of the single-toothed member 21, asdistinguished from a multitoothed or gear member engaging more than oneconvolution at a time of the cam-course, enables us to give thecam-course any direction desired in different parts of its length, solong as its pitch is not made so steep as to destroy the locking action.A uniform movement of the steering-lever can therefore be made to resultin an increase or decrease in the relative rate of turning of thesteering wheels in different parts of the stroke of the steeringdover.

Figs. 5 to 7 illustrate an embodiment of our invention in which a barrelcam 27 is employed in place of the flat cam shown in the precedingfigures, said barrel cam being rotated from the steering-spindle bybevel-gearing 1118, as before, and having a multiconvoluted groove 28,occupied by a roller-stud 25 upon a lever 21, mounted in the same manneras before explained. The are of movement of the stud 25 during therotation of the barrel cam is very nearly parallel to the axis of saidcam. In this form of construction the groove 28 is rectangular in shape,and there is the same absence of backlash and capability of imparting adifferent pitch to different parts of the cam-groove as in the formerembodiment, the only diiference in construction being that the groove ofthe barrel cam is a coil of general helical form, while that of the fiatcam 14 is a coil of general spiral form.

We claim 1. In a steering mechanism, the combination of aguiding orsteering member, a rotary cam having one or more complete turns orconvolutions of a coiled or nonreturning groove of uniform width, amovable cam-engaging member connected with said guiding member andhaving a single circular stud closely fitting said groove at all pointsin the operating length thereof and movable in a path which remainssubstantially normal to rotary cam-like locking member, adownwardly-projecting arm connected with said 15 member and movable byits rotation, and a substantially horizontal link connecting the lowerend of said arm with the said steering connections.

In testimony whereof we have aflixed our 26 signatures in presence oftwo Witnesses.

FREDERICK E. ALLEN. RAYMOND H. DANFORTH. Witnesses-z P. W. PEZZETTI, A.D. HARRISON.

